1. Field of the Invention
The invention relates generally to environmental technology and more specifically to a method for the decontamination of a contaminated material such as soil, mud, sludge, or other material contaminated with substance(s) such as a hazardous waste, hazardous substances, hazardous constituents, pollutant, contaminant, hazardous material, or petroleum.
2. Background
As public awareness has increased regarding the detrimental effects of pollution, environmental laws and regulations for the protection of human health and the environment have become more strict. The disposal of waste, particularly contaminated waste (e.g., hazardous waste, solid waste, waste contaminated with petroleum, etc.,) has been significantly more regulated. Environmental laws and regulations have made it increasingly more difficult for new sites such as landfills or treatment, storage, and disposal facilities (TSD facilities) from receiving permits to operate from governmental agencies such as the United States Environmental Protection Agency (USEPA) or a State Environmental Protection Agency (State EPA). Additionally, the granting of permits is also affected by complaints from individuals located in the area where the potential landfill or TSD facility is to be operated. A common complaint from such individuals is that they do not want a landfill or a TSD facility located in their neighborhood or community.
While the disposal capacity of landfills and TSD facilities has generally decreased over the years, the amount of waste generated by industry and individuals has increased. This has resulted in a shortage of disposal capacity. Consequently, the cost of disposing of contaminated material has dramatically increased.
In an attempt to alleviate these problems, generators of hazardous waste and TSD facilities that manage hazardous waste are required under federal and state law to minimize hazardous waste and to explain the efforts that they have made in order to accomplish this task. Despite the increased cost of disposal of solid waste and the legal requirements to minimize hazardous waste, the technology for disposal of contaminated material such as contaminated soil has generally remained unchanged. Typically, contaminated material is treated or remains untreated and is disposed of at a landfill. For example, soil contaminated with a hazardous waste is typically treated to comply with the land disposal requirements of state and federal law. The soil is then disposed of at a high cost at a landfill permitted to accept soil contaminated with hazardous waste. Another example relates to soil contaminated with petroleum. Typically, any soil contaminated with petroleum is transported directly to a landfill permitted to accept soil contaminated with petroleum.
Given the high cost associated with disposing of contaminated material and the limited disposal capacity, it is desirable to have a method and apparatus capable of reducing the contaminated material that is actually disposed and the cost of disposing of the contaminated waste.
Techniques of the invention relate to reducing the amount of contaminated material disposed of, and in turn, reducing the cost of disposing of contaminated material. Contaminated material is soil, mud, sludge, etc. contaminated with substances such as hazardous waste, hazardous constituent, pollutant, contaminant, hazardous substance, hazardous material, petroleum, or crude oil. One embodiment of the invention relates to mixing a contaminated material with water in a wet-type mixing and grinding mill and agitating the mixture. The agitation of the mixture produces turbulence that reduces the surface tension of the water. Larger particles are separated from smaller particles of the contaminated material by alternating forces acting in the mixing and grinding mill. In another embodiment of the invention, the contaminated water is exposed to a mechano-chemically activated sorption medium. Other features and advantages of the invention will be apparent from the accompanying drawings and from the detailed description that follows below.